1. Field of the Invention
The invention relates to a heating method using compression heat of gas and a manufacturing method for a semiconductor device. The heating method according to the present invention is most suitably applicable to a field which requires to heat an object to be heated (heat target) uniformly and in a short time.
2. Description of Related Art
A heating process has been indispensable for a manufacturing process for a semiconductor device to activate and crystallize an impurities-doped layer, form a thermally oxidized layer on the surface of a semiconductor substrate, etc. In such a heating process, a thermal treatment which is performed at a high temperature (about 1000.degree. C.) and in a long time (30 minutes to one hour) using an electric furnace (hereinafter referred to as "furnace anneal method") has been usually and widely used. Furthermore, a short-time heating method using infrared radiation (hereinafter referred to as "rapid thermal anneal method") has been developed as a short-time heating method. In addition, a heating method using visible or ultraviolet pulse laser beam (hereinafter referred to as "pulse laser beam") has been studied as a shorter-time heating method. In this case, the thermal treatment can be performed in a shorter time (below one microsecond) by using a pulse beam having pulse width of 100 nanoseconds or less.
Recently, semiconductor devices have been improved to obtain a finer and higher-density structure, and this improvement in design of the semiconductor devices has increasingly required a technique of forming an extremely shallow (below 0.5 .mu.m, for example) impurities-doped layer on a semiconductor substrate. However, in the conventional furnace anneal method, it has been difficult to control a diffusion condition of impurities. In order to overcome this disadvantage, the rapid thermal anneal method has been developed. In this method, the thermal treatment must be continued for about 10 seconds, and thus abnormal diffusion of impurities in a semiconductor substrate cannot be perfectly suppressed.
On the other hand, in the pulse laser beam method, the thermal treatment can be performed in one microsecond or less, and the diffusion of impurity atoms during the heating process can be extremely suppressed (below 0.1 .mu.m, for example). However, this method has a disadvantage that the thermal treatment is ununiformly performed due to inhomogeneity in energy between pulse laser beams (fluctuation of the laser beam) or time variation of laser energy.